So my bus has been running hot on the hills so I thought I would do it a favour before I hit the mountain pass and treat her to a nice radiator clean. No luck, so today I replaced the thermostat... Now she's reading hot even at idle (previously idle around 170 and highway driving around the 210 mark) today's outcome has her reading 210 at idle. I hit it with a inferred thermometer and the temps were reading much lower, back in the 150's range... So I took it for a spin up a big hill, 4 miles of 7% grad. Whilst on my way up the coolent alarm came on, never did the gauge drop below 210 so I was kinda hoping it was a disrepency and a bad sensor. Well then it happened and for the first time my engine warn light came on (and remains on) I pulled the bus around and brought her Down the hill. She now sounds funny, a strange glug to it.... I hit it with the IR thermometer again and it seemed hot but nothing out of the of ordinary for that kind of pull. Now the engine is a t44e international turbo deisel 7.3
Could anyone please guide me through how to change my temp sensor (is this an easy task?) can anyone tell me what the engine warn light relays too.... I have no idea why it's sounding like the way it is... I'm getting close to 30k in the hole, in the middle of nowhere and feeling so exhausted and helpless right now. Any advice would be appreciated.

Can I try removing the thermostat all together? Imput please I'm pretty desperate.
Have tested the radiator for exhaust fumes and not getting anything. Other then replacing The whole radiator which would cost me close to a grand and I have no idea how I would even source one in the middle of nowhere.....

Do you now if your water pump is good? A reasonable test is checking if the cabin heaters in the back are getting hot water which would prove you have circulation. The serpentine routing of the 7.3 is pretty complicated.

I would run it without a thermostat and see how hot it gets. heck also for white smoke out of the exhaust . That indicates a head gasket or worse.

Does it run on all 8 cylinders? Does the engine shake , vibrate,
Is the exhaust flow nice even or can you feel / hear puffs?

May some of the experts can chime in about 7.3 .
Can the overheat alarm disable some cylinders and force it into a limb mode?

You say you've put in a thermostat and cleaned the radiator. It's still running hot. It's likely one of 3 things.

1. Low coolant, which I assume you've checked/filled.
2. Fan (or fan clutch) is not doing its job. Or something is not letting air move through the radiator.
3. Failing or failed water pump. It might be accompanied with a slipping/squealing belt.

You should not need a new radiator (hopefully) unless the old one is losing coolant.

Ok so it was a hell of a day yesterday for me and thanks to those who got back to me.
I had a hard time locating a thermostat from where I broke down, the one I changed out must of caused more problems then the original one. In the end I let it cool down, gutted the thermostat and reinstalled the empty ring so it's just on open circuit. This seems to have helped Immensely. Back down to my comfortable driving temps but still need to avoid any big pulls. Fan resistance was good as far as I could tell, current radiator doesn't seem to be leaking at all, fins are fine. After Cooling down the engine warning light clicked off, the 'glug' disappeared and audiably the engine appears to be running normal again. As for my heaters I have them isolated under the engine bay, the rear heater Lines were cut at an earlier date and two quarter turn valves were installed to bypass that route. Maybe I'll look at repairing that circuit as a form of additional emergancy cooling when I have acess to the tools.
Thanks for your input, it was a stressful day for me, great to have acess to this awesome comunity when stuck in the middle of nowhere. Cheers, Buka (made it safely to Salt Lake City)

There are a bunch of vintage buses being used as Hippie camping rentals down in Monroe at a wonderfully wacky camping & RV area called Mystic Hot Springs. That is where I found my '46. He planted a bunch of old cast iron tubs on the hillside where the springs spew out 125 degree water and the minerals have encrusted them into the hillside. Very...unique.

Oh wow this sounds amazing, saddly my day has taken another turn. Pulled over down town and noticed coolent leaking once again. Turns out my thermostat housing was damaged in the process so needs to be replaced... Oh and I finally identified my overheating problem, it's my fan clutch as you guys suggested so will need to get one air freighted up from Vegas tonight... There goes another $1500
Thanks for the tip I think I'll need a long hot soak in one of those to take my mind off things.

fan resistance by finger isnt a good judge of the fan clutch... you have to warm it up and see what the RPM of the fan is... if you ruin a moderate pull and you see the temp approaching 210.. stop, open the hood, rev the engine and see if the RPM of the fan blade stays constant in that 300-450 RPM range.. measurew the AIR TEMP of the air coming from the radiator.. if its really low you have circulation issues.. if its really high (170 or above) and your fan still wont spin up with revs then your clutch is bad.. my bad clutch stayed in that low RPM range all the time which moved planty of air at idle or city traffic but a highway pull and I got warm... believe me when the clutch engages youll knoiw... the fan will slowly spin up to a roar over the engine.... and then slowly spins down as the air temp decreases (usually decreasing coolant temp)...

an air solenopid fan clutch kicks on and off instantly with a higher pitch wait due to a different fan blade in use than ob a viscous clutch..